Molecular characterization and expression analysis of the transferrin gene in Amur ide (Leuciscus waleckii) in response to high alkaline stress

Abstract

Transferrin plays an important role in iron metabolism and has been reported to be involved in the immune response to environmental stress. In this study, the transferrin gene (LwTf) from Amur ide (Leuciscus waleckii) was cloned and characterized. The cDNA was observed to contain an open reading frame (ORF) of 1998bp and encode a 665-amino-acid-long protein that shares 73.04% identity with the transferrin from silver carp (Hypophthalmichthys molitrix). Amino acid alignment analysis showed that LwTf contained an initial peptide and two lobes (N- and C-lobes). Quantitative real-time PCR (qPCR) analyses showed that the expression levels of LwTf were abundant in the liver of the fish but were also significant in the brain and spleen, with lower expression observed in six other tissues. The temporal expression profiles were detected during the alkaline challenge experiment in alkali-water and freshwater populations of healthy adult Amur ide. LwTf expression was significantly upregulated in the main immune organs (spleen, kidney, and head kidney) of the freshwater Amur ide population compared to that in the alkali-water Amur ide population. Taken together, these results indicate that in Amur ide, LwTf might play an important role in the innate immune response to a high alkaline stress.

Keywords

• transferrin
• amur ide (leuciscus waleckii)
• gene expression
• immunity
• high alkaline stress